Earthquakes are usually caused by the movement of tectonic plates in the Earth's crust. But recently, the Mars InSight lander has recorded the very first seismic signal but we have yet to determine its cause.
The new seismic event was too small to provide solid data on the Martian interior, which is one of InSight's main objectives. The Martian surface is extremely quiet, allowing SEIS, InSight's specially designed seismometer, to pick up faint rumbles. In contrast, Earth's surface is quivering constantly from seismic noise created by oceans and weather.
Earth's conditions are a bit different from Mars but despite the environment, InSight was well-equipped for these types of phenomena and so they were able to pick it up through the SEIS instrument, which is in itself a remarkable feat of engineering.
On Earth, high-quality seismometers often are sealed in underground vaults to isolate them from changes in temperature and weather. InSight's instrument has several ingenious insulating barriers, including a cover built by JPL called the Wind and Thermal Shield, to protect it from the planet's extreme temperature changes and high winds.
It was through a collaboration of efforts from various agencies that this groundbreaking event took place.
SEIS has surpassed the team's expectations in terms of its sensitivity. The instrument was provided for InSight by the French space agency, Centre National d'Études Spatiales (CNES), while these first seismic events were identified by InSight's Marsquake Service team, led by the Swiss Federal Institute of Technology.
(Image credit: NASA/JPL-Caltech)